Design of a novel optical delay line based on ring resonators and microcomb for beamforming in a phased array radar

Abstract

Phased array radars, due to their agility in scanning space and high flexibility of radiation pattern, constitute a significant group of radars. However, due to their dependence on the phase to frequency shifters, these radars suffer from a “beam squint”, which limits the radar bandwidth. Using the TTD (True Time Delay) technique is one of the suggested solutions to this problem. Due to the unique features of optical circuits, the TTD method has been widely adopted but problems such as high complexity, high cost, and large size of structures are the challenges these circuits face. In this paper, a ring resonators-based delay line with a microcomb laser source and new construction is presented that, while enjoying the conventional advantages of these rings, is simpler in structure and requires fewer rings than other conventional configurations.